There is this site un**-us.com which supposedly allows you to bypass ISP rules such as content restriction on a particular area. Now , it is well known that routing your traffic through a web proxy yields the same result. But, here this site uses DNS server to unblock you. I do not understand how that is possible. How can having a different DNS server exhibit the same behavior of that of a proxy IP ?

I assume they are google's DNS servers ? This is interesting. This would also mean that the site I've mentioned does not "do anything" right ? since I can always change my DNS to 8.8.8.8. But how do you say that it is very cheap when compared to say, checking the IP address for geographic location ? p.s. I dont have enough Reps, could you please flag the below comment by user12102
–
sudhackerAug 9 '12 at 17:24

1

@user12102 yeah I'll flag that post, no problem. Yeah those are Google's DNS server. Its cheap to impalement a DNS blacklist, by just modifying BIND's configs, you don't even have to write any software for this. Having a proxy server and then forcing people to use this proxy server is complex to install and more difficult to write.
–
rookAug 9 '12 at 17:31

1

@Rook "Cheap to impalement a DNS blacklist"? You're going to run it through with a halberd, or something? ;-)
–
IsziAug 9 '12 at 17:35

Any ISP can break the Google Public DNS workaround by 1. transparently MITMing those IP addresses and 2. instructing tech support to disclaim DNSSEC support entirely.
–
tepplesDec 13 '14 at 18:03